How do I change volume?

Ok so my options menu is basic...brightness, resolution, and volume.
Is there any way to change volume completely? not just for an entity but for the entire game like most games do?

once again I solved my own problem lol. Maybe I should start giving it 24 hours at least. I have been working on both problems for more than 10, but o well..


Solution:

master_vol controls all volumes i believe